Web presses are often used in large-scale printing operations. In typical web press devices, a continuous roll, or “web,” of substrate (e.g. paper) is continuously fed through a print engine in the press. As the substrate is fed through the print engine, one or more colorants may be applied to the substrate by the print engine to form desired text and/or images on the substrate. The use of a web of substrate generally provides the advantage of enabling the press to feed the substrate through the print engine without having to individually feed separate sheets of paper, thus saving time and simplifying substrate loading procedures. After an image has been printed on the substrate, the printed portion of the substrate may be cut according to desired dimensions.
In some cases, web presses may include two or more printing engines operating in tandem to achieve increased productivity. For example, “dual” web presses typically combine two print engines such that the two print engines print on opposite sides of the substrate. However, these devices require synchronization between the print engines as the substrate advances in order to simultaneously print the correct images on both sides of the substrate while maintaining a specified document print order and alignment between images printed on both sides of the substrate. Accordingly, a great deal of development effort has been made to achieve this level of hardware and software synchronization between the print engines.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.